| Title | Wideband Electromagnetic Dynamic Acoustic Transducer as a Standard Acoustic Source for Air-coupled Ultrasonic Sensors |
| Publication Type | Conference Paper |
| Year of Publication | 2019 |
| Authors | Kang, Lei, Feeney, Andrew, Somerset, Will, Dixon, Steve |
| Conference Name | 2019 IEEE International Ultrasonics Symposium (IUS) |
| Keywords | acoustic coupling, acoustic source, Acoustics, air-coupled ultrasonic measurement, flexural ultrasonic transducer, Human Behavior, microphones, pubcrawl, Receivers, Resiliency, Scalability, Sensors, Transmitters, Wideband, wideband electromagnetic dynamic acoustic transducer |
| Abstract | To experimentally study the characteristics of ultrasonic sensors, a wideband air-coupled ultrasonic transducer, wideband electromagnetic dynamic acoustic transducer (WEMDAT), is designed and fabricated. Characterisation methods, including electrical impedance analysis, laser Doppler vibrometry and pressure-field microphone measurement, are used to examine the performance of the WEMDAT, which have shown that the transducer has a wide bandwidth ranging approximately from 47 kHz to 145 kHz and a good directivity with a beam angle of around 20@ with no evident side lobes. A 40 kHz commercial flexural ultrasonic transducer (FUT) is then taken as an example to receive ultrasonic waves in a pitch-catch configuration to evaluate the performance of the WEMDAT as an acoustic source. Experiment results have demonstrated that the WEMDAT can maintain the most of the frequency content of a 5 cycle 40 kHz tone burst electric signal and convert it into an ultrasonic wave for studying the dynamic characteristic and the directivity pattern of the ultrasonic receiver. A comparison of the dynamic characteristics between the transmitting and the receiving processes of the same FUT reveals that the FUT has a wider bandwidth when operating as an ultrasonic receiver than operating as a transmitter, which indicates that it is necessary to quantitatively investigate the receiving process of an ultrasonic transducer, demonstrating a huge potential of the WEMDAT serving as a standard acoustic source for ultrasonic sensors for various air-coupled ultrasonic applications. |
| DOI | 10.1109/ULTSYM.2019.8926271 |
| Citation Key | kang_wideband_2019 |
Wideband Electromagnetic Dynamic Acoustic Transducer as a Standard Acoustic Source for Air-coupled Ultrasonic Sensors